Laser annealing is a treatment technique that causes transformation of a crystal lattice of a semiconductor or metal through thermal action by laser beam irradiation. The advantages are that only a necessary portion can be treated locally, it is possible to shorten the treatment time by annealing at a high energy density, and the like. Such laser annealing, applied for various usages, is an irreplaceable treatment technique in the high-speed manufacturing process of liquid crystal displays that have been increasing in size. For high-definition panels of thin-film-transistor (TFT) liquid-crystal displays that are currently mainstream, low-temperature polysilicon (LTPS) TFTs have been widely used. Laser annealing is used for treatment in which an amorphous silicon film in a TFT-forming area is locally irradiated with a laser beam and made into polysilicon (for example, see Patent Literature 1 below).